There are many methods of joining two pieces of material. The prior art upon which significant improvements will be described is that of the classic dovetail joint.
In the description that follows, the classic dovetail joint will be referred to as a base for explanation. The dovetail joint is a joint most commonly used for drawer construction in high-quality furniture. A dovetail joint is a modified finger joint where a reversed, wedge-shaped finger or pin fits into a matched socket formed by a pair of tails. (The socket, formed by a pair of tails, will be referred to simply as xe2x80x9cthe tailxe2x80x9d or xe2x80x9ctailsxe2x80x9d.) The shape of the pins and of the tails into which they are inserted resemble the spread of a dove""s tail, hence the namexe2x80x94a dovetail joint.
The dovetail form creates a joint that is secured in one direction without dependence on glue or other fastening methods. When the joint is fastened or glued, movement is controlled in all directions, making this type of joint extremely strong.
A series of dovetails may be used to lock two boards together, such as in a drawer, creating a comer that is highly desirable due to its strength and durability.
In addition to great strength and durability, many find the dovetail joint to be visually pleasing and indicative of quality woodwork.
With the many benefits offered by a dovetail joint, one must ask the question: why is this joint not used to a greater extent in construction techniques? The answer is fairly simplexe2x80x94dovetail joints can be difficult to assemble. Due to the tight tolerance requirements, errors in fabricationxe2x80x94not keeping within the required tolerances, damage to the pins or tails prior to assembly, or a slight swelling of the pins or tails (due to moisture) prior to assembly can make it difficult to assemble the dovetail joint.
As an amateur woodworker there is a type of project I have enjoyed over the years. I have made numerous enclosures to be used outdoors as sandboxes, raised gardens, flowerbeds, planters around a mailbox post, and the like. On many of these projects, the joints have failed over time, pulling apart. In analyzing the failure of these jointing methods I have recognized some of the problems associated with this type of application. I believe that a dovetail joint could solve many of the jointing shortcomings.
Modern technology has greatly facilitated the cutting of dovetail joints with the use of jigs, templates, special dovetail router bits, power tools, etc. The greatest problem with the dovetail joint is the difficulty of assembling the joint if there is any swelling of materials, damage to pins or the tails that make up the joint, or fabrication that is out of tolerance in cutting the dovetails.
A new solution to the dovetail joint challenge, and the basis for this NEW INVENTION is slightly tapering the pins and their corresponding tails, in the same direction; a new jointing method I am calling a tapered dovetail joint. This new joint incorporates the benefits of the classic dovetail jointxe2x80x94strength, durability and aesthetically pleasing to some, while significantly increasing the ease of assembly. The tapered design allows for a loose fit of the joint as the two pieces are brought together. Once joined, the tapered dovetail creates a tight joint with characteristics similar, or superior to the classic dovetail joint. The tapers compensate for minor tolerance deviations in fabrication, defects or damage to the pins or tails that may have occurred, by allowing a loose fit initially. As the two pieces are brought together the clearance between the contact sides of the pin and the contact sides of the tail decrease gradually (the joint begins to tighten) until the units are brought into full contact and the union is made. The tapered dovetail joint offers many advantages over traditional dovetail joints. A few of these advantages are explained for a better understanding of the technology:
Ease of Alignment
One of the greatest advantages that the tapered dovetail offers over traditional dovetail s is its ease of assembly. The joint is easy to assemble due to the initial clearance as the joint is being assembled. This will be explained further in the text of this document.
Reduced Need for Tight Tolerances in Fabrication
Closely related to the ease of alignment issue is the reduced need for tight tolerances. If a joint has not been cut to tight tolerances, such as those required for a classic dovetail joint, this joint can be driven together into full union due to the initial clearance at the initiation of joint union. The wedging action that takes place during the assembly process may compensate for minor inaccuracies in fabrication as well as damage after fabrication that may have occurred.
Elimination of Starved Joints
When a classic dovetail joint is assembled, it is common for the majority of glue that has been placed on the pins and tails to be forced out of the joint due to tight tolerances. This creates a starved joint, or a joint with insufficient glue. The tapered nature of the tapered dovetail joint allows a much greater amount of glue to remain on the contact surfaces until contact is made between the two components.
Greater Strength of the Tapered Dovetail
When a classic dovetail joint is assembled it is normal for there to be some destruction of the wood fibers during assembly. This occurs as the pins are driven into the tails due to tight tolerances. The tapered nature of the tapered dovetail joint minimizes the contact and friction between the two pieces until the point at which the two components are brought into full union.
As stated above, I have recognized the advantages of tapering the pins and the tails of a dovetail joint, creating the tapered dovetail joint, which can be more easily assembled, but preserves many of the positive qualities of a traditional dovetail joint.
It is, therefore, an object of this present invention to provide a tapered dovetail joint that will be more easily assembled than the classic dovetail joint due to the slight tapering of the dovetail pins and tails. This joint will have improved strength characteristics, similar durability, and a similar appearance to other dovetail joints.
It is the specific object of this present invention to provide the details of the tapered dovetail joint; where the tapered dovetail pins are slightly tapered, and the dovetail tails have a corresponding angle of taper. The mating of this dovetail joint will be greatly facilitated due to these corresponding tapers. The tapered nature of this joint will minimize the difficulties in assembly that would have otherwise been caused by damage to the tails, damage to the pins, swelling of tails and/or pins that may take place from time of manufacture to time of assembly, as well as minor manufacturing tolerance deficiencies in cutting of the pins and tails.
Some of the primary advantages offered by this new method of joining include: 1) The ease of alignment between the two elements to be joined; 2) Reduced need for tight tolerances in fabrication and assembly; 3) Elimination of starved joints; and 4) Greater strength of the joint inherent to its design.